Riest 2008.

Study characteristics
Methods	Study design: parallel‐group randomized controlled trial Sample size: 160 Country: Germany Setting: secondary care hospital Dates conducted: not reported Postoperative opioid used and delivery: morphine PCA Pain score collection: trained nurse Concurrent postoperative analgesics: none reported
Participants	Inclusion criteria Discectomy Aged 18‐88 years old Exclusion criteria Mental or physical inability to handle a PCA ASA > 3 Preoperative opioids Administration of steroids or NSAIDs within 24 hours before skin incision Allergy against sulphonamides or NSAIDs Severe liver dysfunction Congestive heart failure History of myocardial infarction Stroke Pulmonary embolism Gastrointestinal bleeding Refusal Pregnancy and/or lactation
Interventions	Group Perioperative (80 participants): 40 mg IV parecoxib 45 minutes before surgery and 12 and 24 hours after surgery Group Postoperative (80 participants): placebo 45 minutes before surgery and 12 and 24 hours after surgery
Outcomes	Postoperative pain (average pain score over 24 hours using 0‐10 VRS and BPI) Morphine consumption (mg at 25 hours) Opioid adverse events (using SDS at 25 hours) Adverse events (myocardial infarction, stroke, pulmonary embolism, deep vein thrombosis or gastrointestinal bleeding during follow‐up)
Notes	Funding: "Investigator initiated trial funded by Pfizer, Germany. Pfizer did not participate in generation of the study design or interpretation of results". Declarations of interest: as above Authors contacted: no Other: unable to include opioid adverse events as not individually reported. Pain not included as average used
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated. Quote: "...randomization with a computer‐generated random list"
Allocation concealment (selection bias)	Unclear risk	No mention
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐dummy placebo used
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No mention
Incomplete outcome data (attrition bias) All outcomes	High risk	Many patients excluded but unclear to which groups they belonged. Quote: "43 patients were excluded before assessment of the primary criteria for the following reasons..."
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration
Other bias	Unclear risk	No baseline characteristics table. Industry funded but stated no involvement in study